Although raceways have been available for use in a corner, that is between a wall and a ceiling, and between 90° walls, such raceways have in the past had corners that are of a particular form dictated by the respective shapes of the raceway base. See for example European Patent No. 600,108 wherein a convex cover is hingedly connected to one side of the raceway base, is that the opposite side of the cover can be snapped in place after providing the wiring or cables therein.
In another European Patent, No. 887,903, a corner raceway is shown having a generally flat cover, with flared marginal edges and depending ribs adapted to be received in grooves provided along the marginal edges of the base sidewalls.